RESUMEN
This paper is aimed to assess the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) and bone marrow stromal cell (BMSCs) composited tricalcium phosphate (TCP) in a rat model of posterolateral lumbar intertransverse process fusion. Rat BMSCs were cultured in vitro. Twenty SD rats underwent single-level bilateral intertransverse process spine arthrodesis at L4 and L5. These rats were assigned to two groups according to the graft materials. They received: 10 of the total were treated with the BMSCs with rhBMP-2 and tricalcium phosphate (TCP) as the experimental group, and the other 10 with TCP treatment alone as the control group. All the animals were killed at 4 weeks after surgery and the spine fusion results were assessed by gross inspection, manual palpation, radiography and histology. The fusion rate, the tensile strength and stiffness of the solidly fused levels in the experimental group were statistically higher than that of the controlled group (P < 0.05). These results showed that the spinal fusion could be improved mechanically when rhBMP-2 and BMSCs were added into the TCP.